Fix memory leak in the mp3 decoder, turned out to be of pretty decent size (bug #395)

src/modules/sound/lullaby/Mpg123Decoder.cpp

@@ -68,7 +68,7 @@ namespace lullaby
 
 	Mpg123Decoder::~Mpg123Decoder()
 	{
-		mpg123_close(handle);
+		mpg123_delete(handle);
 
 	}